A drive apparatus for vehicle has heretofore been known as including a differential device through which an output of a drive power source, such as an engine or the like, is distributed to a first electric motor and a transmitting member through which the output thereof is mechanically transmitted to an output shaft of the drive apparatus, and a second electric motor between the transmitting member and drive wheels. A drive apparatus, disclosed in Patent Literature 1, includes a planetary gear unit as a differential device having a differential action through which a major part of power delivered from the engine is mechanically transmitted to drive wheels while enabling a remaining part of power from the engine to be electrically transmitted from a first electric motor to a second electric motor using an electrical path. Accordingly, a vehicle is made available to run with the engine maintained under an optimum operating state, enabling fuel consumption to be improved.
[Patent Literature 1] Japanese Patent Unexamined Application Publication No. 2003-191759
[Patent Literature 2] Japanese Patent Unexamined Application Publication No. 2003-191761
[Patent Literature 3] Japanese Patent Unexamined Application Publication No. 2003-336725
Such a conventional drive apparatus for vehicle includes an electric path for electric energy to be delivered from the first electric motor to the second motor, that is, a transmitting path through which a part of a drive power of the vehicle is transmitted in electrical energy. Therefore, with the development of the engine operating at a high output, the first motor needs to have a large size in structure. In addition, a need arises to increase a size of the second electric motor driven with electric energy output from the first electric motor. Thus, a problem arises for the drive apparatus to have a large size in structure.
The present invention has been made on the ground of the circumstances described above and has an object to provide a drive apparatus for vehicle that can be miniaturized in structure.